Telecommunications systems, cable television systems and data communication networks use optical networks to rapidly convey large amounts of information between remote points. In an optical network, information is conveyed in the form of optical signals through optical fibers. Optical fibers comprise thin strands of glass capable of communicating the signals over long distances with very low loss. Optical networks often employ wavelength division multiplexing (WDM) or dense wavelength division multiplexing (DWDM) to increase transmission capacity. In WDM and DWDM networks, a number of optical channels are carried in each fiber at disparate wavelengths, thereby increasing network capacity.
An optical signal comprised of disparate wavelengths and modes may experience optical dispersion. Optical dispersion is an often undesirable phenomenon that causes the separation of an optical wave into spectral components with different frequencies. The separation of waves into spectral components with different frequencies may be referred to as chromatic dispersion (CD). Additionally, optical dispersion causes the separation of different modes (e.g., polarization states) of each frequency. The separation of waves according to the different modes of a frequency may be referred to as polarization mode dispersion (PMD). Optical dispersion may refer to both CD and PMD and occurs because the differing wavelengths and modes of wavelengths may propagate at differing speeds. The separation of an optical wave into its respective channels and modes due to optical dispersion may require optical dispersion compensation for the particular optical signal.
Additionally, optical signal parameters such as channel power, channel wavelength, and optical signal-to-noise ratio (OSNR) may vary among each channel due to the wavelengths of the channels being affected differently within an optical network. Accordingly, these parameters may also require monitoring for proper network operation.